The embodiments herein relate generally to material storage units for use in subterranean formation operations and, more particularly, to particulate dust control and fill management of material storage units for use in subterranean formation operations.
Subterranean wells (e.g., hydrocarbon producing wells, water producing wells, and the like) are often stimulated by hydraulic fracturing treatments where fractures are formed in a subterranean formation and held open with solid particulates (referred as “proppant”) to enhance fluid conductivity through the formation. Often, many tons of particulates are used in a fracturing operation. Such particulates are also used, among other operations, during gravel packing operations to control sand production in a subterranean formation during production, for example. As used herein, the term “particulate” refers collectively to proppant particulates, gravel particulates, and any other solid particulates that may be used in a subterranean formation operation.
When preparing particulates at the surface of the well site for use in an operation, large amounts of dust may be created by the movement of the particulates, thereby creating inhalation hazards. For example, a common particulate (e.g., proppant particulate, gravel particulate, and the like) is sand, which produces silica dust that is associated with the lung disease silicosis, or Potter's rot. Silicosis is a type of pneumoconiosis that manifests as inflammation and scarring in forms of nodular lesions in the upper lobes of the lungs, which may result in severe difficulties breathing and low blood oxygen levels.
A material storage and transport unit (collectively referred to herein as “material storage unit”), for example, is a piece of particulate-handling equipment that can produce dust during the transfer or movement of particulates. The material storage unit may also be used to transport the particulates. For example, generally, particulates are transferred from a manufacturer or other storage containment to a material storage unit for transport and storage at the well site. The material storage unit is typically equipped with a pneumatic or gravity fed discharge outlet for conveying the particulates to a location outside of the material storage unit, such as a mixer. The mixer is generally where water and other additives (e.g., viscosifiers, surfactants, friction reducers, resins, tackifiers, and the like) may be mixed with the particulates, such as to form a slurry for delivery to a downhole location (e.g., to stimulate a subterranean formation).
Material storage units are typically configured such that the particulates are filled into one or more bins in the unit with one or more pneumatic fill line inlet in each bin. The pneumatic fill line inlet may extend from the bottom of each bin in the material storage unit and pneumatically convey the particulates into the bin. As the pumping takes place, a significant amount of dust is typically produced. To monitor the contents of the material storage unit and ensure that the bins in the material storage unit are not overfilled, operators typically observe the filling process from the top of the bin, where a hinged hatch may be present that may be opened to view the contents of the bins. However, the dust may accumulate and escape through the hatch thereby exposing operators to significant dust. The significant amount of dust particularly when coupled with worker proximity during operation creates a substantial exposure risk.
When dust control measures are used, they are most commonly in the form of the hatch previously discussed, which may be ineffective as a consequence of the need to open the hatch despite the produced dust. In some instances, a vacuum system with a hose may be used, but a vacuum connection is required for each individual bin and dust exposure to the operator is not eliminated, as the operator still must monitor the filling process through an opening in the bin to ensure that overfilling does not occur.